Simplify the following expression: $y = \dfrac{k^2 + 14k + 45}{k + 5} $
Explanation: First factor the polynomial in the numerator. $ k^2 + 14k + 45 = (k + 5)(k + 9) $ So we can rewrite the expression as: $y = \dfrac{(k + 5)(k + 9)}{k + 5} $ We can divide the numerator and denominator by $(k + 5)$ on condition that $k \neq -5$ Therefore $y = k + 9; k \neq -5$